Surgical fasteners, or staples, are commonly used in surgical procedures to allow a surgeon to fasten body tissue together without the need for time consuming suturing procedures. The surgical fasteners can be applied to the body tissue by using surgical staplers which operate to install the fasteners one at a time or to apply a plurality of fasteners in succession or simultaneously. The staplers typically include fastener cartridges from which the fasteners are driven into the tissue.
Two-part surgical fastener devices are previously known. Such devices include a fastener member, or staple, which is generally U-shaped in configuration with a pair of prongs, and a receiver member provided with apertures in which the prongs are engaged and latched. The fastener prongs pierce the body tissue from one side and the receiver member latches the prongs on the other side of the tissue. The surgical fasteners, once engaged, are not separable so that, after being inserted into the body tissue, the fasteners cannot be easily removed. Accordingly, two-part surgical fasteners usually consist of bioabsorbable material which is absorbed into the body tissue.
In the past, hernia repair procedures have been performed by open surgery in which an elongated incision is made in the body wall for access to the internal body tissue to be repaired. Such open surgery is traumatic to the patient and a long recovery period is required for the incision to heal. Typically, the hernia repair is performed by conventional suturing techniques. A hernia repair patch, if used, is secured to the internal body tissue by sutures applied along the edges of the patch.
More recently, endoscopic instruments and techniques have been developed to perform surgery on internal body tissue, including hernia repairs. Such procedures are performed by installing an endoscopic tube in a small incision in the body wall and by inserting the surgical instruments into the endoscopic tube to perform the desired surgery. The endoscopic procedures are less traumatic to the patient and result in a shorter recovery period in comparison with open surgery.
In performing hernia repairs by endoscopic surgery, it is necessary to employ surgical fasteners or staples which are capable of securely holding the internal body tissue together. Also, if a hernia patch is installed, the surgical fasteners or staples must be capable of securely fastening the hernia patch to the internal body tissue. The endoscopic instruments previously used for hernia repair procedures have utilized surgical fasteners or staples made of metal, e.g., titanium or stainless steel. These instruments generally include a staple forming mechanism which forms the surgical fastener from an open position to a closed position penetrating the tissue at the surgical site.
The metal fasteners or staples previously used for hernia repairs remain permanently inside the patient and are not absorbed by the internal body tissue. Such metal fasteners or staples are opaque to x-rays and appear in x-ray photographs of the patient. Thus, it is desirable to employ surgical fasteners or staples of bioabsorbable material for hernia repairs because the fasteners or staples are eventually absorbed into the body tissue and do not interfere with x-ray photographs of the patient. The previous two-part surgical fasteners of bioabsorbable material tend not to be suitable for hernia repairs because of the difficulty of obtaining the access to both sides of the tissue to be repaired. Accordingly, a receiverless fastener of bioabsorbable material is highly desirable for hernia repairs and other surgical procedures on internal body tissue. Also, it is advantageous to provide a self-closing receiverless fastener which avoids the need for using a surgical instrument with a forming mechanism to secure the fastener to internal body tissue.